The U.S. Department of Energy Office of Science has announced the selection of five Small Business Innovation Research (SBIR) and one Small Business Technology Transfer (STTR) projects for funding. The six FY18 Phase I Release 1 projects target critical materials advances in solid-state lighting (SSL) technology, and will explore the technical merit and commercial potential of innovative concepts or technologies that are expected to contribute to the achievement of the price and performance goals described in DOE’s SSL R&D Plan.
The SBIR-STTR program seeks to increase the participation of small businesses in federally sponsored innovative and novel research and development. To learn more about this program, visit http://science.energy.gov/sbir/.
The six SBIR-STTR grants directly related to SSL are briefly described below:
SBIR Recipient (Phase I): Pixelligent Technologies LLC (Baltimore, MD)
Title: Improved Light Extraction for a 130 lm/W OLED Lighting Panel
Summary: By studying the fundamental principles of light extraction applied to high-refractive-index layers that are embedded with scattering particles, Pixelligent proposes to advance the relevant materials science used to create internal extraction layers (IELs) for use in OLED panels. It is hoped that this effort will produce pathways to overcome a major challenge to widespread manufacture and commercial-scale production of OLED panels used for general illumination. Presently, OLEDs are limited by low light extraction efficiency, even though they have very high internal light production efficiency. Successful completion of the proposed research will allow OLED panels and, eventually, luminaires to have general-illumination product efficiencies comparable to or better than competitive LED luminaires, but with more desirable color, form factor, and lower cost. The Phase I effort will include the creation and characterization of advanced structures and the evaluation of their performance in a well-characterized OLED device manufactured by OLEDWorks. The goal of Phase I will be to make an OLED with > 100 lm/W at 2700 – 3000 K and 3,000 cd/m2, and in Phase II the goal will be to improve the efficiency to 130 lm/W.
SBIR Recipient (Phase I): Lumisyn, LLC (Rochester, NY)
Title: New Class of Encapsulants for Blue LEDs
Summary: Based on Lumisyn’s prior work on nanocrystals for efficient and stable downconversion, this project will explore the prospect of employing related structures into and in formation of the encapsulating matrix, as a potential replacement for the ubiquitous silicones used in the phosphor-converted LED (pcLED) industry today. Improvements to thermal conductivity result in the advantageous reduction of LED junction temperature, thereby allowing higher driving power while also avoiding conditions of droop and nonradiative losses. There are numerous fundamental materials challenges that limit thermal conductivity of such structures or that cause unwanted scattering or other optical losses. Each of these materials challenges will be systematically explored and overcome if the project is successful. If successful, achieving the 2020 and 2025 DOE goals for thermal conductivity are possible. The project is also expected to result in the production of novel encapsulants that enable improvements in outcoupling from conventional GaN LEDs by systematic modification of refractive indices. The enhanced outcoupling is projected to lead to further improvements of future pcLED efficacies.
SBIR Recipient (Phase I): OLEDWorks, LLC (Rochester, NY)
Title: High efficacy bendable OLEDs composing flexible glass, printable internal extraction and anode layers and a multi-stack OLED structure
Summary: This project will focus on use of Willow GlassTM or plastic as primary candidates for development of a new, flexible substrate as a foundation to eventually manufacture a high-performance, stable, and cost-effective printable internal extraction layer (IEL) for OLEDs. The proposed work includes development of compatible anode technology on a barrier-coated substrate leading to the manufacture of OLED panels compliant with applicable DOE price and performance projections. There are many technical challenges with both flexible substrates, but in either case, surface modification of the substrate will be necessary to ensure adequate adhesion and flexibility of the subsequent IEL, anode, and OLED layers. Anode designs that do not include ITO, including Ag nanowires and the use of special buffer layers or films containing scattering particles, will also be explored to achieve a baseline performance goal of 90 lm/W. When produced with an optimized OLED stack, printable IEL, and silver nanowire anode on a suitable flexible substrate, the resulting OLED will achieve an efficacy > 100 lm/W at a warm-white color of about 3000 K, <0.004 Duv and at a brightness of 3,000 cd/m2.
STTR Recipient (Phase I): PhosphorTech Corporation (Kennesaw, GA)
Title: Stable Perovskite Core-shell Nanocrystals as Down-Converting Phosphors for Solid State Lighting
Summary: The team, including Georgia Tech Research Institute (GTRI), will seek to develop stable perovskite core-shell nanocrystals (NCs) as alternatives to conventional inorganic downconverting phosphors. If successful, these NCs will be incorporated into current RadiantFlexTM sheets manufactured by the applicant, to demonstrate the production of high-luminous-efficacy (~200 lm/W), warm-white, high-brightness pcLED devices using remote or proximate phosphor configurations. Achieving this novel and potentially more efficient goal will require the development and optimization of perovskite core-shell NCs and their encapsulation into stable silica matrices. The key for achieving this goal will be the synthesis of highly efficient core-shell perovskite nanostructures with tunable Stokes shift. The color-tunability and reduced bandwidth of these nanomaterials can be optimized to create high-color-quality white LED emission. Such LEDs are expected to have higher luminous efficacies than existing pcLED materials and comparable or improved thermal stability. Perovskite NCs can potentially be used in any downconversion LED architecture and could allow the subsequent manufacture of higher-brightness LED light engines at competitive prices than is possible using conventional designs.
SBIR Recipient (Phase I): Sinovia Technologies (San Carlos, CA)
Title: Roll-to-Roll Patterned Integrated Substrates for OLED Lighting
Summary: Sinovia, in collaboration with Vitriflex, Inc., has developed an integrated substrate for OLED lighting using a flexible plastic medium with exceedingly low water vapor transport (10-6 g/m2/day); variable sheet resistance, ranging from 1 to 10 ohms/sq; and greater than 75% transparency. With Ag nanowires embedded in the surface of a barrier-enhancing polymer layer, the transparent conductive film does not require ITO. These substrates have been shown to improve white OLED efficiency between 30% and 50%, with lifetimes approaching 80% of those typically achieved using ITO-coated glass. Sinovia proposes to use high-throughput flexographic printing to pattern this substrate roll-to-roll. If successful, this enabling technology will accelerate OLED panel manufacture by reducing manufacturing costs for flexible OLEDs that have efficacy and lifetime comparable to those of conventional OLED architectures built on glass substrates. More importantly, the use of integrated flexible substrates allows OLED manufacturers to develop high–speed roll-to-roll processes that would dramatically reduce costs and waste. Furthermore, the availability of efficient, warm-white, flexible OLED panels would have a profound and lasting positive effect on market penetration of OLEDs into the general-illumination marketplace.
SBIR Recipient (Phase I): Solution Deposition Systems, Inc. (Goleta, CA)
Title: Dual Function OLED Transparent Electrode and Light Extraction Layer
Summary: Solution Deposition Systems proposes the development of a dual-function transparent electrode and light-extraction enhancement layer for eventual use in the economic manufacture of OLEDs for SSL applications. The research and development proposed under this project will seek to leverage Solution Deposition Systems’ technology for aqueous solution deposition of transparent conductive ZnO-based materials. The proposed ZnO layer will be deposited on inexpensive soda-lime float glass and offers cost advantages in raw materials, reduced capital equipment expense, and manufacturing expenses compared to ITO, while still providing performance competitive to other transparent conductive layers. Importantly, the proposed technology also allows for control over the refractive index and scattering coefficient of the ZnO layer, which will enable an OLED light-extraction enhancement of 2.5 times or more compared to current ITO layers with no outcoupling enhancement layer. Subcontractor Princeton University, under the direction of Professor Barry Rand, who specializes in OLED outcoupling techniques, will fabricate and test OLED devices using the ZnO layers that are developed.